da181dc974
The specification (PCIe r5.0, sec 6.1.4.5) states:
For MSI-X, a function is permitted to cache Address and Data values
from unmasked MSI-X Table entries. However, anytime software unmasks a
currently masked MSI-X Table entry either by clearing its Mask bit or
by clearing the Function Mask bit, the function must update any Address
or Data values that it cached from that entry. If software changes the
Address or Data value of an entry while the entry is unmasked, the
result is undefined.
The Linux kernel's MSI-X support never enforced that the entry is masked
before the entry is modified hence the Fixes tag refers to a commit in:
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Enforce the entry to be masked across the update.
There is no point in enforcing this to be handled at all possible call
sites as this is just pointless code duplication and the common update
function is the obvious place to enforce this.
Fixes: f036d4ea5fa7 ("[PATCH] ia32 Message Signalled Interrupt support")
Reported-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.462096385@linutronix.de
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.